A quantum dot is an electrostatic potential well that confines a small number of electrons (as few as one) to a region tens of nanometers in scale. We would like to use the spin of a single electron (spin-1/2) as a quantum bit (qubit), and to arrange these qubits together scalably to form building blocks for large-scale quantum information processors.
We have studied quantum dots formed in nanowires, carbon nanotubes, and two-dimensional electron gases in GaAs and Silicon. Our current focus is on Silicon metal-oxide-semiconductor (MOS) devices based on the potential for qubits with long coherence times in isotopically purified silicon and the potential for large large scale integration via commercial CMOS technologies. Our work spans theory/simulation and experiment, and is principally motivated by our published proposal for a scalable quantum processor based on a node/network approach.